停—升—停多项式凸轮曲线族

提出三个多项式凸轮曲线族。使用者可根据不同的用途，用优化方法求得待定系数值，从满足边界条件的曲线族中挑选出一条综合性能最优的凸轮曲线。还提供了待定系数与所选凸轮曲线的诸特性值之间关系的图表。     

聚合色素膜的极化及二次谐波产生的研究

对键合偶氮染料的聚合素薄膜，进行分子二阶非线性光学性能测定，结果表明：极化时间、温度及电场强度等因素对二次谐波的产生具有显著的影响。本实验中，极化时间以２０－３０ｍｉｎ，极化温度在该聚合物的Ｔｇ附近，极化电压以５ＫＶ为宜。比较了聚合色素与染料－聚合物掺杂系统两种情况下，二次谐波随时间的变化，结果是前者比后者具有更高的稳定性。可见，聚合色素膜比掺杂系统更有希望成为实用化的非线性光学材料。     

Nonlinear excitation profiles for three-dimensional inflow MR angiography

An RF excitation pulse for three-dimensional (3D) time-of-flight (TOP) MR angiography (MRA) with a nonlinear excitation profile was numerically calculated under the condition of uniform vessel signal across the excitation volume (slab), and the superiority of the optform pulse as compared with conventional RF pulses and TONE pulses was demonstrated. For this purpose we acquired MRA of the lower leg and of the carotid and vertebral arteries in a 30-year-old healthy volunteer. Although the flow velocity ranges in these two anatomic locations are different by about a factor of 10, in both cases the corresponding optform pulse provided the best signal homogeneity at the highest level.     

胆道支撑管显影材料的制备及体外细胞毒性评价

目的 探讨新型显影胆道支撑管材料制备的可行性，对构建出的材料进行体外细胞毒性评价和筛选。方法 选择具有X线下显影特性的基础材料A、B、C，分别与硅橡胶生胶共混炼，模压后分别得到相应的显影复合材料甲、乙、丙，经一段和二段硫化过程完成加工。采用MTT法作为体外细胞毒性评价的方法，测定参比对照材料和新材料的50％浓度的浸提液对小鼠成纤维细胞的增殖率的影响，确定细胞毒性级别。结果 新材料甲、乙、丙在x线下影像清晰。甲、乙材料的细胞毒性级别为零，丙材料细胞毒性级别为2。结论 构建出在X线下显影的弹性体材料可行。材料甲、乙是制造新型胆道支撑管的初选材料，材料丙无应用的价值。     

如何提高医学素材数码摄影的画面效果

介绍了数码影像技术在图像画面拍摄中的应用,使医学素材具有真实性和艺术性相结合的画面效果,从而提高了教学质量.     

化疗药物外渗后局部组织损伤处理的实验研究

目的根据化疗药物外渗后局部组织损伤的特点寻找理想的处理方法。方法制作化疗药物外渗的动物坏死模型,分别采用临床常用的三种处理方法进行动物实验,进行肉眼观察及组织学观察。结果1∶5 000呋喃西林加季德胜蛇药外敷对化疗药物外渗所致的局部组织坏死疗效最佳,其次为复方利多卡因,50%硫酸镁外敷疗效甚微,对照组无效。结论临床处理化疗药物外渗应根据其局部特点选择合理有效的方法。     

Pulmonary and haemodynamic effects of extracorporeal circulation in the cat and the beneficial effects of prostacyclin

Side-effects of a veno-venous extracorporeal system and possible beneficial effects of prostacyclin (epoprostenol) are analyzed on the cat. Three groups were studied; one control group without extracorporeal circulation and two groups with an extracorporeal flow of 10–12 ml/kg/min, one of which was given prostacyclin (70–110 ng/kg/min). The extracorporeal circulation triggered a decrease in arterial saturation (from 99 to 91 %) and carbon dioxide elimination (increase in arterial to end-tidal PCO₂ by about 1 kpa) a metabolic acidosis (pH7.20), a platelet consumption (50%) and shortened survival time, side-effects reduced by prostacyclin. Further, there was a marked increase in haemoglobin concentration indicating hypovolemia via capillary fluid filtration. None of these side-effects were seen in the control group. Extracorporeal circulation as a trigger for pulmonary dysfunction and for impaired tissue nutrition with possible beneficial effects of prostacyclin is discussed, and also from a clinical point of view (i.e. extracorporeal lung assistance, ECLA), on the basis of the results.     

S-99和S-100止血作用研究

PT、APTT、TT、血小板粘附率和血栓形成试验表明S-99可溶性止血纺织材料和S·100吸收性止血綾的止血效果无显著差异。但是S-99和S-100止血纺织材料的止血机理不尽相同,S-100止血绫主要是通过溶解后的负电性液相激活内源性止血系统;而S-99止血纺织材料主要是通过溶胀胶粒粘附血小板,进而激活血小板。     

纤维/颗粒增强聚乳酸骨折内固定复合材料

现将骨折内固定材料的发展史，传统骨折内固定材料的不足之处，以及开发可吸收骨折内固定材料的意义作一综述。介绍了聚乳酸作为可吸收内固定材料的优异性能，及其复合材料的特点，并比较了以聚乳酸为基体的各种内固定复合材料的成型工艺和机械力学强度。     

Model building on the basis of Dutch cervical cancer screening data

A mass screening programme for cervical cancer is in progress in three pilot regions in The Netherlands. All women living in these regions aged 35-53 are invited to undergo screening at three-year intervals. The MISCAN simulation model was developed for the analysis and optimization of screening programmes. In this paper the model-based approach to evaluation is first outlined and then illustrated by analysing data from the first two screening rounds in the pilot regions. This analysis resulted in a rather restricted range of data-compatible assumptions for the mean duration of preclinical disease (14-19 yr) and the frequency of spontaneous regression of preinvasive lesions (45-65%), as well as a rather wide sensitivity range for the Pap smear (50-90%). These preliminary findings are compared with those of a previous MISCAN analysis of cervical cancer screening in British Columbia. On the basis of an assumed 18-yr duration, 50% regression and 70% sensitivity, a number of screening policies relating to the same age ranges but with different intervals are compared. Both the analysis and the policy comparisons are preliminary, but the findings are nevertheless reasonable and consistent with those of previous studies. A more complete MISCAN-based analysis of the Dutch screening programme and subsequent optimization of screening policies will be possible when further results become available and a cost-effectiveness analysis procedure has been incorporated into the MISCAN programme.